1. Field of the Invention
The present invention relates to a locking apparatus for an openable window that is disposed in a cabin provided with a beam.
2. Description of the Related Art
JP 2005-146781A discloses a window opening and closing apparatus in a cabin that is provided with an openable window and a locking arm, wherein the openable window can be opened and closed while being swingably supported on a frame forming the cabin, and the locking arm locks this openable window in a half-closed state. This window opening and closing apparatus is provided for an openable window functioning as a rear window of a tractor cabin. The window opening and closing apparatus is provided with the locking arm that is swingably supported on an upper face of a lower frame (a beam made of square pipe). The front end side of the locking arm has a half-lock striker that locks the rear window in a half-closed state, and the base end side has a full-lock striker that locks the rear window in a fully-closed state (closed state). A swinging axis of the locking arm is in a direction orthogonal to a longitudinal direction of the lower frame (a normal direction of the frame upper face). With such a configuration, when the half-lock striker and the rear window become engaged with each other by the rotation of the locking arm along the upper face of the lower frame, the rear window is locked in the half-closed state. Furthermore, when the full-lock striker and the rear window become engaged with each other, the rear window is locked in the fully-closed state.
However, according to the apparatus described in JP 2005-146781A, the locking arm extends along the upper face of the lower frame when the rear window is in the fully-closed state. That is to say, the locking arm is positioned on the upper side of the lower frame throughout the full length of the locking arm, and, thus, this locking arm obstructs rear vision.
In view of these circumstances, there is a demand for a locking apparatus in a cabin, which, to the fullest extent possible, does not obstruct vision through an openable window that is to be locked.